[The effect of post-biopsy scar on the submucosal elevation for endoscopic resection of rectal carcinoids]

While endoscopic resection could be considered as the best choice for the treatment of small rectal carcinoid, the colonoscopic biopsies performed at the time of detection may lead to scar and ulcer formation and cause unpredicted difficulty in the endoscopic resection. This study was evaluated to analyze the relationship between the post-biopsy scar and the limitation of submucosal elevation for the endoscopic resection of rectal carcinoids.

Twenty two cases of rectal carcinoid which received prior biopsies before the endoscopic resection were retrospectively compared with 20 non-biopsied cases. All two groups were treated by endoscopic resection from January 2000 to December 2007. There was no difference in the clinical characteristics and endoscopic findings such as size and location between the two groups.

The limited submucosal elevation was experienced in 17 cases (77%) in the biopsy group, significantly more frequent than 9 cases (45%) in the non-biopsy group (p=0.03). The colonoscopic findings which contribute to difficult submucosal elevation were the depressive scar formation after biopsy, the size less than 5 mm in the biopsy group, active ulcer formation after biopsy. Regarding the resection method, endoscopic submucosal dissection was frequently adopted (23% vs. 5%) in the biopsy group. The frequency of endoscopic piecemeal resection in biopsy group was higher than non-biopsy group (23% vs 10%), and all cases were subsequently resected by other endoscopic methods.

The post-biopsy scar can interfere with successful submucosal elevation for endoscopic resection of rectal carcinoids. The number of forceps biopsy should be minimized in the diagnostic colonoscopy when endoscopic resection is planned rectal carcinoids.